Telephone system.



Patented June 13, 1911.

HpP. GLAUSEN.

TELEPHONE SYSTEM. APPLICATION FILED OCT. 25, 1901.

THE NORRIS PETERS cw. WASHINGTON D. q.

"barman "earner errrcn HENRY P. CLAUSEN, OF CHICAGO, ILLINOIS, ASSIGNOR, BY MESNE ASSIGNMENTS, TO STROMBERG-OARLSON TELEPHONE MANUFACTURING COMPANY, OF ROCHESTER, NEW YORK, A CORPORATION OF NEW YORK.

TELEPHONE SYSTEM.

Specification of Letters Patent. Patented Julie 13, 1911.

Application filed October 25, 1901. Serial No. 79,899.

To all whom it may concern:

Be it known that I, HENRY P. CLAUsnN, a citizen of the United States of America, and resident of Chicago, Cook county, Illinois, have invented certain new and useful Improvements in Telephone Systems, of which the following is a specification.

My invention relates to telephone systems in general, but more particularly to systems in which magnetos are employed at the substations for operating the calling signals at the central station, and in which complete metallic circuits are employed between the substations and the central station.

Generally stated, the object of my invention is to provide certain details and features of improvement tending to increase the general efiicie-ncy of a telephone system.

Certain special objects are to provide a circuit arrangement which will enable the central operator to answer a call without producing objectionable or unpleasant sounds in the receiver at the substation, and which will cause the calling signal to remain displayed or in operation until the call is answered by the operator, it being also an object of my invention to provide a circuit arrangement which will permit the current which lights the calling signal lamp to be supplied through a local circuit of comparatively low and unvarying resistance.

To the foregoing and other useful ends, the magneto at the substation is preferably normally in circuit through a condenser with a relay and battery at the central station. The relay and battery are also arranged to form a part of a local circuit which is closed when the relay is operated by a call sent in from the substation. When the magneto at the substation is operated, said relay at the central station is operated and the movement of its armature causes the current of the battery to flow through the short circuit for the purpose of operating the calling signal. This calling signal can be of any suitable or approved form, but is preferably in the nature of an incandescent lamp arranged in the local circuit and adapted to be lighted by the current from the battery when the relay is operated by the magneto at the substation. In this way,

the relay is first operated by the magneto at the substation, and after its armature closes the local circuit it then continues to be energized by the said battery which furnishes the current for lighting the calling signal-lamp. The current from the battery through the relay holds the local circuit closed and keeps the calling signal displayed until the call is answered by the operator. The local circuits and condensers can be so arranged that when the operator answers the call and cuts out the battery for the purpose of restoring or extinguishing the calling signal lamp, there will not, as a result of thus breaking a circuit, be any objectionable or unpleasant sounds caused in the receiver at the substation. In other words, the operator in restoring the calling signal simply opens up a local circuit and does not cut out the calling signal battery or break a circuit in such manner as t6 have the effect of such break extend to and be audible in the receiver at the substation.

The arrangement has the further advantage of permitting a call to be made over a line circuit of comparatively high resistance, and of permitting a calling signal to be maintained in operation by the current from the battery through a local circuit of comparatively low and unvarying resistance.

The nature and advantages of my invention will, however, hereinafter more fully appear.

The accompanying drawing is a diagram illustrating a telephone system embodying the principles of my invention.

As thus illustrated, the telephone system may, for example, comprise substations S and S, having suitable line connection with the central station. At the central station are the usual spring jacks forming the terminals of the subscribers lines, in this case indicated by J and J. Connection between the two substations thus illustrated is effected through the medium of a cord circuit having the plugs P and P. The cord circuit and the jacks and also the substation apparatus may be of any suitable or approved form, but it will be observed that magnetos M are preferably employed at the substations for the purpose of operating the i L the central station,

'1 the system to no r i e a be Echo J c om p be operate played for se of attracting tention of opera such operator the subscriber at substation 5 desires connection with a subscriber lVhen the ma at some other cu neto hf subtron S is operated, a c rent is thereby caused to flow from this ringneto throuoh a circuit formed by the line lei, condenser 13, relay armature 12, contact point 11, i e 1"), relay R, lamp L, line 5), line ccnnew ons 8 and 7, and thence through the battery into the ground at E. 'lhe circuit is then completed from E ough the ground to the ground conne on 6, thence through contact points through an mature e and line connection 3, the es through the receiver-hook or switch H to the contact-point 2, and finally through the bell l to the said magneto M. A. current from the magneto in flowing through this circuitcauses the armature 1' of the relay B to more into contact with the adjacent contact points 16 and 1?. The operation of the relay R in this manner closes a short circuit a .d thereby establ shes a short local circuit through which the current from battery 13 is allowed to flow for the purpose of lighting the lamp ation.

L. This short local circuit comprises the connections 7 and 8 leading from the bat-- the battery 13 through a short local circuit l of which the lamp l1 and the relay are a part. This, as stated, causes the calling signal L, which is'preferably a lamp, to be displayed, and in this way, the operator is i In advised of the call from substation S. order to answer the call and to ascertain the number of the substation with which thecalling subscriber des 'i-es connection, the operator then inserts the plug P of the cord circuit in spring-jack J, which latter, it will be observed, forms the terminal of the line connection with substation S. The insertion of plug P in jack J operates to complete a circuit from battery B through line connections 7, 8 and 2st, to relay R, from this relay through connection 23, spring 22, through contact 21 and line 20 to ground at 19, thence through the ground to E and back to the battery B. This circuit, it will. be understood, is established by the insertion or restore the calling signal words, when a current troin battery B is t thus completed places the *ith' the lamp L and the relay R, by attracting the l and 12, serves to open up the described circuit of which the is a part, ant to thereby extinguish L. ln other caused to flow through the cut-out relay R, the latter breaks or opens up the circuit for the relay R, thereby releasing the armature r and permitting the latter to move away from the points 16 and 17, In this way, the insertion of the cord plug P cuts out the relay R and extinguishes or restores the calling signal L, and at the same time the relay E, by attracting its armatures 4: and 12 stablishes connection between the substation and the operators talking set in the cord circuit. ll hen the arinatures 4: and 12 are attracted by the magnet of the relay R, a circuit is thereby completed which establishes connection between the substation S and the listening key K of the cord circuit. The operator then presses the listening key K and, as stated, the substation S is then in communication with the taking set in the operators cord circuit. lVhen the listening rey K is pressed by the operator, a circuit is immediately completed from the operators receiver 27 through the secondary 28 of the induction coil, through contact 29 and key K to the sleeve 80 of the plug P, through the ring 31 of 'jack J to contact 32, thence through the armature 12 and the condenser 13 to line 1%, through the latter to the con neotion 33, thence through the receiver 25 and the conductor 3% to the secondary 35 of the induction coil, through contact 36, receivericok or switch H, to line 3, through the latter to art iature at, thence through contact 87, string contact of the jack to the tip 39 a P, thence through connection 40 to contact 25, and finally through back to the receiver 27. At oint l also be seen that the operators tter 48 is inductively connected with the substation through the medium: of the pr ary d6 of the induction coil, and that the t ing current for the operators set is supplied from battery B through connections 7, 45, the primary 46 of the in duction coil, connection 4", the transmitter 48, connection i9, and thence through the impedance coil 50 to ground connection 51, and from the latt r through the ground to the ground connection E, and thence back to the battery B,

It will be understood that after a call is sent in from substation S, the receiver 6 is lifted from the hook H, so as to bring the latter into contact with the adjacent contact points 36 and 41. In this way, the line is in condition to permit communication to be established, as explained, between the operator and the subscriber at substation S.

When the operator at the central station learns the number of the substation called for by the subscriber at substation S, the calling plug P is then inserted in ack J for the purpose of establishing connection between the operators ringing key and the substation S, which latter is assumed to be the substation with which the subscriber at station S desires connection. The insertion of the plug P in the spring ack J, and the pressing of the ringing key K by the operator, establishes a circuit from the magneto G through connection 55 to contact point 54, from the latter through key K and connection 40 to plug-tip 39, from the latter to jack spring 38, and thence through contact point 37 and armature 4: to line 3, through the latter to receiver-hook or switch H at substation. S, from this hook or switch to contact point 2 through bell 1 and magneto M to line 1 1-, thence through the condenser 13 and armature 12 to contact 32, from the latter through the ring or casing 31 of the jack J to plug sleeve 30, from this sleeve of the plug to ringing key K, from the lat ter to contact point 57, and thence through. connection 56 to the magneto G. The operator then operates the magneto G, and the current thereby generated causes the hell 1 at substation S to ring. The subscriber at substation S then lifts the receiver 5 of this station ofli the hook H, thereby bringing the receiver-hook or switch into contact with the adjacent contact points 41 and 36 of this station. At this juncture, it Will be understood that the insertion of plug P in jack J causes the contacts 22 and 21 to come together, thereby completing the circuit from battery 13 to the right through connections 7 and 2st to cut out relay R, from the latter through 23, 22, 21 and 20 to 19, thence through the ground to E and back to the battery B. This, it will be seen, draws the armatures 4t and 12 of relay B into contact with the contact points 32 and 37, and, as explained, establishes electrical connection between the operators magneto G and the bell 1 at substation S. Electrical connection being thus established between substation S and the plug P, the operator then releases the ringing key K, thereby establishing connection between the line of substation S with the cord circuit. The subscribers at substations S, S, are now in communication with each other through. their respective 'lines, and through the medium of the cord circuit connecting the plugs P and P. The circuit thus completed for the purpose of permitting the two subscribers to communicate With each other, consists of line 3 from substation S, through armature l of relay R, through contact 37 and jack spring 38 to plug-tip 39 of plug P, through connections 10 and 52 to ringing key K, through the latter and the connection 10 to tip 39 of plug P, from this plug-tip to jack-spring 38, and from the latter to contact 37, from this contact through armature at to line 3 of substation S, through this said substation to line l4,thence through condenser 13 to armature 12, through contact 32 to jack ring or casing 31, thence to the sleeve 30 of plug P, from this plug sleeve to ringing key K, from this said ringing key to contact 58, and thence through connection 59 to sleeve 30 of plug P, from this plug sleeve to the ring or casing 31 of jack J, thence through contact 32 and armature 12 and the condenser 13 to line 1 1 of substation S, and thence through substation S to the line 3.

It will be observed that the talking current is supplied by the batteries 13 at the substations, and that in talking at substation S, for example, the circuit is completed from line 3 through the transmitter T to battery 43, through the primary 41-2 of the induction coil, thence through contact 41 and the receiver-hook or switch H, and inductively through the induction coil to line.

1%. In this way, the system permits the two subscribers to communicate with each other in the usual well-known manner.

The clearing-out signal, by which the central operator is advised that the conversation is at an end, and that the subscribers have hung up their receivers, consists, in this case, of the relay I, adapted to operate a suitable drop or clearing-outsignal. hor example, when the receiver at substation S is hung up, the subscriber operates the magneto M for the purpose of advising the operator that the plugs may be removed for the purpose of disconnecting the two substations. When the receiver is thus hung up, a circuit is completed from the magneto M of station S, through line 14 to condenser 13, thence through relay armature 1.2 to contact 32, through the ring or casing 31 of jack J to the sleeve 30 of plug P, thence through connections 59 and 61 to relay 1, through this relay and connections 60, 52 and 4-0 to tip 39 of plug P, from this plug-tip to jack spring 38 of the jack J, thence through con tact 37 and armature 4 to line 3, from this line 3 through the receiver-hook or switch H to contact 2, and thence through the bell 1 to the magneto M. The subscriber at substation S can then operate the magneto, and the current thereby generated will cause the relay I to operate the clearing-out signal. This clearing-out signal, as stated, may be of any suitable form or character, and, when displayed, advises the central operator that the subscribers have hung up their receivers and rung oil. The operator then withdraws the plugs P and P from the jacks J and J of the respective substations, and the system is then in its normal or inoperative condition.

In answering the call sent in from sub station S, it will be observed that the operator causes the operation of cut-out relay R, and that in so doing the relay R and lamp L are cut out as a result of the short circuit through which these devices are operated being broken or opened by the attraction of the armatures 4 and 12 to the magnet of the relay R. It will be observed, however, that the condenser 13 is interposed in the line, and that in thus restoring the calling signal only a short circuit is broken, and that consequently the effect of this break is not electrically communicated to the substation S, and that consequently this break will not extend to and be audible in the receiver at said station. In this way, the circuit arrangement permits the central operator to answer a call and to break a circuit for the purpose of restoring the calling signal without causing an objectionable or unpleasant sound in the receiver of the substation from whence the call came. It is apparent, therefore, that the circuit arrangement operates to quiet the line, and, at the same time, that the advantages of certain approved apparatus and methods of operation are retained. Furthermore, the circuit arrangement has the advantage of enabling the battery B to light the calling signal lamp L through a short local circuit of comparatively low and unvarying resistance. I

The magneto M is employed for initially energizing the relay R, it being observed that the magneto current is carried over a line circuit of comparatively high resistance. The operation of the relay R by the magneto current in this manner, is, however, sufiicient to close the short circuit formed by connections 18 and 15 which, it will be observed, are in the nature of a short circuit connection extending between the line terminals at the central station. Thus the magneto current is employed, as stated, for initially energizing the relay R, and when once the short local circuit is closed, this relay continues to be energized by the current of battery B. Thus the call sent in operates to display the calling signal, and this signal continues to be'displayed until the operator in answering inserts the plug of the cord circuit in the spring jack. In other words, the calling signal is capable of looking or holding itself in operation until the cut-out relay is operated by insertion of the plug and regardless of the condition of the apparatus at the substation.

The condensers 13 not only form a gap in the line and thereby tend to quiet the latter in answering calls, but also serve as a means for preventing the constant displaying of the calling signals. Furthermore, the jacks, it will be observed, are normally disconnected from the lines, and are only connected to the latter when the cut-out relays are energized by the insertion of the plugs. Practically, therefore, the jacks are normally insulated both from the line and from the ground. This also is instrumental in quieting the lines and in eliminating the effects or conditions which would tend to annoy the listening subscribers. In addition, it will be seen that each line relay is part of both the line and local circuits. In this way, each line relay is initially energized through a line circuit, and is then permanently energized by being included in the local battery circuit-that is to say, it is energized by the local circuit until the answering plug is inserted in the jack. The conductors 15 and 18, together with the armatures and contact-points of the relays R, constitute normally open short-circuit connections across the line terminals at the central station. When closed, these short circuit connections operate to short-circuit the substations, regardless of the interposition of the condensers 13. In other words, when these short-circuit connections are closed, the substations will be cut off whether condensers are inserted in the line or not.

' ith the local batteries 43 at the substations,

and with the centralized battery B at the centralexchange, it will be observed that the system is of the central energy type, cur rent for the signals being furnished from a common battery, but the current for talking purposes being furnished from local batteries.

It will be readily understood that any suitable arrangement can be employed for making the busy testthat is to say, for testing the line of a called subscriber, where the eX- change is of the multiple switch-board type, as by touching the tip of the plug to the thimble or testing ring of the multiple jack, connected with the called subscribers line, in the usual and well-known manner.

I claim as my invention,

1. In a telephone system, the combination of signal devices by which the subscriber signals the operator, a substation and a central station, complete metallic line connection between said stations, and a condenser included in the talking circuit and located in one limb of the line at the central station together with a battery at the central station for supplying current to the signal devices by which the subscriber attracts the attention of the operator at the central station.

2. In a telephone system, the combination of a subscribers line, a subscribers magneto normally connected with both sides of the line, a normally open short-circuit connection across the line terminals at the central station, a relay normally connected with the line and arranged to be energized by said magneto, said relay when energized closing the short-circuit connection, a battery at the central station, and a normally open local circuit including said battery, relay and short-circuit connection.

3. In a telephone system, the combination of a subscribers line, a subscribers magneto connected wit-h the line, a normally open short-circuit connection across the line terminals at the central station, a line relay connected and arranged to be initially energized by said magneto, the said short-circuit connection being closed when the relay is energized, a line signal and a battery at the central station, and a normally open local circuit including said battery, line signal, line relay and shortcircuit connection.

l. In a telephone system, the combination of a subscribers line, a spring-jack normally disconnected from the line, a line.

signal, means at the substation for operating said line signal, and a condenser included in the talking circuit and located in the line at the central station for preventing the constant display of said line signal together with means for connecting the ack to the line, and a battery for furnishing current to said line signal.

In a telephone system, the combination of a subscribers line, a spring jack normally insulated both from the line and the ground, a line signal, means at the substation for operating said line signal, a condenser included in the talking circuit and located-in the line at the central station for preventing the continuous display of said line signal, and a cut-out relay for restoring the line signal and establishing connec tion between the jack and the line.

6. In a telephone system, the combinatioii of a subscribers line, a line lamp connected with a battery at'the central station, a line relay, means at the substation for initially energizing said line relay, a spring jack normally insulated both from the line and the ground, a condenser in the line at the central station, a normally open short-circuit connection across the line terminals at the central station, a normally open switchpoint for said short-circuit connection, said switch-point being controlled by said line relay, and a cut-out relay for restoring the line signal and establishing connection be tween the jack and the line.

7 In a telephone system, the combination of a subscribers line, a normally open short-circuit connection across the line terminals at the central station, a relay connected with the line and arranged to control a normally open switch-point in said short circuit connection, and a magneto at the substation adapted and arranged for energizing said line relay and thereby closing said short-circuit connection.

8. In a telephone system, the combination of a subscribers line, a line relay normally connected with the line, a line lamp in series with said line relay, and a subscribers magneto connected and arranged for projecting a current through the said relay and lamp.

9. In a telephone system, the combination of a subscribers line, a line relay, a line lamp arranged in series and normally connected with the line, a centralized battery connected in series wit-h said relay and lamp, and a subscribers magneto connected and arranged for projecting a current through said relay, lamp and battery.

10. In a telephone system, the combination of a subseribers line, a normally open short-circuit connection across the line terminals at the central station, a line relay normally connected with the line and arranged to control a normally open switchpoint in said short-circuit connection, line lamp and a battery connected in series with said line relay, and a subscribers magneto connected and arranged for projecting a current through said relay, lamp and battery, so as to initially energize the relay, the said-circuit connection when closed including the relay, lamp and battery in a local circuit,

11. In a telephone system, the combination of a subscribers line, a spring jack normally disconnected from the line, a. condenser in the line at the central station, a line lamp normally connected with the line at the central station, a battery connected with said lamp, and a subscribers generator connected and arranged for projecting current through said lamp and battery together with means for connecting the jack to the line.

12. In a telephone system, the combination of a substation equipped with local battery apparatus, a central station provided with a centralized signaling battery, suitable line connection between said stations, a normally open short-circuit connection acrossrthe line terminals at the central station, a line relay connected with the line and arranged to control said short-circuit connection, and means for initially energizing said relay.

13. In a telephone system, the combination of a subscribers line, a normally open shortcircuit connection across the line terminals at the central station, a condenser in the line at the central station, a line relay normally connected with the line, a battery connected with said relay, a line lamp arranged in series wit-h said relay and battery, said relay being arranged to control said short-circuit connection, a subscribers magneto at the substation for initially energizing said relay, the latter when energized closing the shortcircuit connection and thereby including itself and the latter and also the lamp and battery in a local circuit, and manually operated means for deenergizing said relay and thereby restoring or extinguishing said lamp.

14. In a telephone system, a substation and central station and line connection between the same, a condenser in the line, a relay and calling signal and a battery for operating the same at the central station, a short circuit connection between the terminals of the line at the central station, said short circuit connection being normally open but closed when the relay is operated, a magneto at the substation adapted to operate said relay for the purpose of displaying the calling signal, the relay when operated by the magneto establishing a short local circuit through the short circuit connection, said relay being a part of said local circuit for the purpose of holding such local circuit closed until the call is answered, substantially as described.

15. A telephone system comprising a substation and a central station and a line connection between the same, a relay and a battery normally connected through a condenser with the line of said substation, a magneto at the substation normally in circuit with the line, and a short circuit connection between the line terminals at the central station, said short circuit being normally open but closed when the relay is operated by rotating the armature of said magneto, and the said short circuit when closed cutting out the substation and establishing a short local circuit through which the current of said battery flows until the call is answered by the operator at the central station, substantially as described.

16. A telephone system comprising a substation and a central station and a metallic line connection between the same, a magneto at the substation for effecting the operation of said calling signal, a battery at the central station, a lamp calling signal arranged to be lighted by said battery, a short circuit connection between the terminals of the line at the central station, said lamp battery being normally in circuit for calling purposes with the magneto at the substation, a relay for closing said short circuit connection and thereby causing the current from said bat tery to flow through said lamp, and a cut-out relay operative to break said circuit for the purpose of extinguishing or restoring said lamp, said cut-out relay being energized when the operator answers the call, substantially as described.

17. In a telephone system, the combination of signal devices by which the subscriber signals the operator, sub-station apparatus, central station switchboard apparatus, line connection between said sub-station apparatus and said switchboard apparatus, and a condenser in the line between the sub-station apparatus and the switchboard apparatus, together with a battery at the central station for supplying current to the signal devices by which the subscriber attracts the attention of the operator at the central station.

18. In a telephone system, the combination of sub-station apparatus, central station switchboard apparatus, complete metallic line connection between the two stations, the line circuit being normally closed at the substation, said switchboard apparatus involving a battery and electromagnet normally connected in series with the said sub-station apparatus, and a condenser in the line between the sub -station apparatus and the switchboard apparatus, said condenser serving to prevent a continuous energizing of said electro-magnet.

19. In a telephone system, the combination of sub-station apparatus having a local battery for talking, central station switchboard apparatus, a centralized call battery associated with said switchboard apparatus, line connection between the said switchboard apparatus and sub -station apparatus, said switchboard apparatus involving a spring jack normally disconnected from the line, an operators cord circuit provided with a plug for insertion in said jack, and a relay connected with said centralized call battery and adapted to connect the jack with the line when the plug is inserted, said switchboard also involving a calling signal adapted to be controlled by the sub-station apparatus and to be operated by current supplied from said centralized call battery.

20. The combination with a calling telephone line, of an individual connection terminal for the line normally disconnected therefrom, means including a normally open connection between the line wire terminals at the central station for automatically short circuiting the line when a call is sent in, and means for automatically connecting said terminal with the line when a connection is established therewith in response to the call, substantially as described, and an electric magnet excluded from the talking circuit for giving a disconnect signal.

21. The combination with a telephone line, of an individual connection-terminal for the line, means for connecting the same with the line, means including a normally open connection between the line wire terminals at the central station for automatically short circuiting the line when a call is sent in, and means for automatically disconnecting the same from the line when not in use, substantially as described, and an electric magnet excluded from the talking circuit for giving a disconnect signal.

22. The combination with a telephone line and an individual connection-terminal for the line, of means including a normally open connection between the line wire terminals at the central station for automatically short circuiting the line when a call is sent in, means for automatically connecting the terminal with the line when in use, and for automatically disconnecting the same therefrom when not in use, substantially as described, and an electric magnet excluded from the talking circuit for giving a disconnect signal.

23. The combination with a calling telephone line and an individual connectiont-erminal for the line normally disconnected therefrom, of means including a normally open connection between the line wire terminals at the central station for automatically short circuiting the line when a call is sent in, means actuated by the act of making connection with the line in response to the call for connecting said terminal with the line, substantially as described, and an electric magnet excluded from the talking circuit for giving a disconnect signal.

24. The combination with a telephone line and an individual connection-terminal for the line normally disconnected therefrom, of means including a normally open. connection between the line wire terminals at the central station for automatically short circuiting the line when a call is sent in, means actuated by the act of making connection with the line for connecting said terminal with the line, and means actuated by the act of unmaking connection with the line for disconnecting said connection-terminal from the line, substantially as described, and an electric magnet excluded from the talking circuit for giving a disconnect signal.

25. The combination with a telephone line and an individual connection-terminal for the line normally disconnected therefrom, of a line signal, means including a normally open connection between the line wire terminals at the central station for automatically short circuiting the line when a call is sent in, a relay distinct from said signal for connecting said terminal with the line, and means actuated by the act of making connection with the line for operating said relay, substantially as described, and an electric magnet excluded from the talking circuit for giving a disconnect signal.

26. The combination with a telephone line and an individual connection-terminal for the line normally disconnected therefrom, ot a signal for said line, means including a normally open connection between the line wire terminals at the central station for automatically short circuiting the line when a call is sent in, a local circuit, a relay distinct from said signal and a source of current therein, and means actuated by the act of making connection with the line for closing said local circuit to actuate said relay and thereby connect said terminal with the line, substantially as described, and an electric magnet excluded from the talking circuit for giving a disconnect signal.

27. The combination with a telephone line and a connection-terminal in the form of a spring-jack or switch-socket, of means including a normally open connection between the line wire terminals at the central station for automatically short circuiting the line when a call is sent in, a connecting plug, means actuated by the insertion of said plug in the socket for connecting said terminal with the line, and means actuated by the withdrawal of the plug for automatically disconnecting said terminal, substantially as described, and an electric magnet excluded from the talking circuit for giving a disconnect signal.

28. The combination with a telephone line and a connection terminal in the form of a spring-jack or switch-socket, of means including a normally open connection between the line wire terminals at the central station for automatically short circuiting the line when a call is sent in, a connecting plug, a relay for controlling the circuit to said connection-terminal, a local circuit including said relay, normally-separated contacts at the switch-socket, and means for closing said contacts by the insertion of the connectionplug in said switch-socket, substantially as described.

29. The combination with a telephone line and an individual connection-terminal for the line, of a signaling device, means including a normally open connection between the line wire terminals at the central station for automatically short circuiting the line when a call is sent in, and means for automatically connecting the terminal with the line and disconnecting the signaling device therefrom, and vice versa, substantially as described, and an electric magnet excluded from the talking circuit for giving a disconnect signal.

30. The combination with a telephone line, of an individual connection-terminal for the line and a signaling device, means including a normally open connection between the line wire terminals at the central station for automatically short circuiting the line when a call is sent in, and means for automatically connecting one of said ele ments with the line and simultaneously disconnecting the other therefrom, substantially as described, and an electric magnet excluded from the talking circuit for giving a disconnect signal.

31. The combination with a. telephone line, of an individual connection-terminal for the line normally disconnected therefrom, a signaling device normally connected therewith, means including a normally open connection between the line wire terminal at the central station for automatically short circuiting the line when a call is sent in, and means 1 net excluded from the talking circuit for actuated by the act of making connect with the line for connecting said term with the line and for disconnecting said s nal device therefrom, substantia-v c scribed, and an electric magnet excluded from the talking circuit for giving a disccnnect signal.

32. The combination with a telephone line, of a connection-terminal, a signaling device, means including a normally open connection between the line wire terminals at the central station for automatically short circuit ing the line when a call is sent in, and means actuated by the actof making con nections with the line for connecting said terminal therewith and for disconnecting said signaling device therefrom and means actuated by the act of unmaking ccnnection with the line for disconnecting said terminal therefrom, and for connecting signaling device therewith, substantially as described, and an electric magnet excluded from the talking circuit for giving a disconnect signal.

33. The combination with a telephone line, of a connection-terminal and a signaling device, means including a normally open connection between the line wire terminals at the central station for automatically short circuiting the line when a call is sent in, and means for automatically connecting said connection terminal and signaling device with, and disconnecting the same from, the line so that both of said elements are never in connection with the line at the same time, substantially as described, and an electric magnet excluded from the talking circuit for giving a disconnect signal.

34. The combination withatelephone line, of a connection-terminal normally disconnee ed therefrom, a signaling device normally connected therewith, means including a normally open connection between the line wire terminals at the central station for automatically short circuiting the line when a call is sent in, a relay, and means actuated by the act of making connection with the line for operating said relay to connect said terminal with the line and to disconnect said signaling device from the line, substantially as described, and an electric magnet excluded from the talking circuit for giving a disconnect signal 35. The "combination with a telephone line, of an individual connection-terminal for the line, means including a normally open connection between the line wire terminals at the central station for automatically short circuiting the line when a call is sent in, a relay for connecting the same with and disconnecting the same from the line, and a test-circuit controlled by said relay, substantially as described, and an electric maggiving a disconnect signal.

36. The combination withatelephone line, of an individual connectienterminal for the line normally disconnected therefron ns including a normally open connection be tween the line wire terminals at the central station for automatically short circuiting the line when a call is sent in, a relay, and means actuated by the act of making connection with the line for operating said relay to connect said terminal with the line, and a test-circuit controlled by said relay, substantially as described, and an electric magnet excluded from the talking circuit for giving a disconnect signal,

37. The combination Withatelephone line, of means including a normally open connection between the line wire terminals at the central station for automatically short circuiting the line when a call is sent in, a relay having a winding included in a local circuit including contacts at a connectionterminal, a pair of springs or other movable parts actuated by said relay, and connected respectively with the limbs of said telephone line, back contacts against which said springs or parts normally rest and a signaling device connected between said back contacts, front contacts with which said springs or parts engage when the relay is energized, and the line-contacts of a connection-terminal connected with said front contacts, substantially as described, and an electric magnet excluded from the talking circuit for giving a disconnect signal.

38, In a telephone system, a line having two limbs extending to a central. ollice, means including a normally open connection between the line wire terminals at the central station for automatically short circuit'ag the line when a call is sent in, a relay having movable contact member for each limb of said line, a signal iicluded in circuit between the back contacts of said members, a spring-jack normally disconnected from said line and having its talking contacts included between the frontcontacts of said relay members, and a local circuit including the coil of said relay controlled at the spring-jack, whereby said signal is disconnected from said line and said jack is connected with said line when a connection is made at the jack, substantially as described, and an electric magnet excluded from the talking'circuit for giving a disconnect signal.

39. In a telephone system, aline having two limbs extending to a central office, means including normally open connection between the line wire terminals at the central station :for automatically short circuiting the line when a call is sent in, a rei lay having a movable contact member for each limb of said line, a signal included in circuit between the back contacts of said members, a spring-jack normally discon nected from said line and having its talking contacts included between the front contacts of said relay members, and a local circuit controlled by additional contacts at the spring-jack, whereby said signal is disconnected from said line and said jack is connected with said line when a connection is made at the jack, substantially as described, and an electric magnet excluded from the talking circuit for' giving a disconnect signal.

40. In a telephone system, the combination of signal devices by which the subscriber signals the operator, a spring jack and a subscribers line, and a condenser in line just outside of said spring jack to gether with a battery atthe central station for supplying current to the signal devices by which the subscriber attracts the attention of the operator at the central station.

41. A telephone system comprising asub- 7 signal, a condenser in the line and a battery at the central station for maintaining said line signal in operation after the current from the magneto has ceased and until the call is answered by the operator.

42. A telephone system comprising means whereby the calling signal is initially operated by alternating current from a substation, and then held in operation by cur rent from the central station, by a winding forming part of the path of each current, and a cut off relay for retiring the line signal when the operator answers the call.

43. The combination with a calling telephone-line, of an individual connection-terminal for the line normally disconnected therefrom, and means for automatically connecting said terminal with the line when a connection is established therewith in response to the call, together with normally bridged bells and generators at the subscribers stations, a line relay, a local circuit for energizing said line relay, and bridging supervisory and ringing apparatus at the central. station.

44. The combination with a telephoneline, ofan individual connection-terminal for the line, means for connecting the same with the line, and means for automatically disconnecting the same from the line when not in use, together with normally bridged bells and generators at the subscribers stations, a line relay, a local circult for ener-- gizing said line relay, and bridging supervisory and ringing apparatus at the central station.

45. The combination with a telephoneline and an individual connection-terminal for the line, of means for automatically connecting the terminal with the line when in use, and for automatically disconnecting the same therefrom when not in use, together with normally bridged bells and generators to the call for connecting said terminal with 1 a the line, together with normally bridged bells and generators at the subscribers sta tions, a line relay, a local circuit for energizing said line relay, and bridging supervisory and ringing apparatus at the central station.

47. The combination with a telephoneline and an individual connection-terminal for the line normally disconnected therefrom, of means actuated by the act of making connection with the line for connecting said terminal with the line, and means actuated by the act of unmaking connection with the line for disconnecting said connectionterminal from the line, together with normally bridged bells and generators at the subscribers stations, a line relay, a local circuit for-energizing said line relay, and bridging supervisory and ringing apparatus at the central station.

48. The combination with a telephoneline and an individual connection-terminal for the line normally disconnected therefrom, of a line-signal, a relay distinct from said signal for connecting said terminal with the line, and means actuated by the act of making connection with the line for operating said relay, together with normally bridged bells and generators at the subscribers stations, a line relay, a local circuit for energizing said line relay, and bridging supervisory and ringing apparatus at the central station.

49. The combination with a telephone-line and an individual connection-terminal for the line normally disconnected therefrom, of a signal for said line, alocal circuit, a relay distinct from said signaloand a source of current therein, and means actuated by the act of making connection with the line and a connectionterminal in the form of a spring-jack or switch-socket, of a connecting-plug, means actuated by the insertion of said plug in the socket for connecting said terminal with the line, and means actuated .by the withdrawal of the plug for automatically disconnecting said terminal, together with normally bridged bells and generators at the subscribers stations, a line relay, a local circuit for energizing said line relay, and bridging supervisory and ringing apparatus at the central station.

51. The combination with a telephone-line and a connection-terminal in the form of a spring-jack or switch-socket, of a connecting-plug, a relay for controllin the circuit to said connection-terminal, a local circuit including said relay, normally-separated contacts at the switch-socket, and means for closing said contacts by the insertion of the connecting-plug in said switch-socket, together with normally bridged bells and generators at the subscribers stations, a line rewith the line and disconnecting the signal-.

ing device therefrom, and vice versa, together with normally bridged bells and generators at the subscribers stations, a line relay, a local circuit for energizing said line relay, and bridging supervisory and ringing apparatus at the central station.

53. The combination with atelephoneline, of an individual connection-terminal for the line and a signaling device, and means for automatically connecting one of said elements with the line and simultaneously disconnecting the other therefrom, together with normally bridged bells and generators at the subscribers stations, a line relay, a local circuit for energizing said line relay, and bridging supervisory and ringing apparatus at the central station.

54. The combination with a telephoneline, of an individual connection-terminal for the line normally disconnected there-- from, a signaling device normally connected therewith, and means actuated by the act of making connection with the line for connecting said terminal with the line and for disconnecting said signal device therefrom, together with normally bridged bells and generators at the subscribers stations, a line relay, a local circuit for energizing said line relay, and bridging supervisory and ringing apparatus at the central station.

55. The combination with a telephoneline, of a connection-terminal, a signaling device, and means actuated by the act of making connection with the line for connecting said terminal therewith and for disconnecting said signaling device therefrom, and means actuated by the act of unmaking connection with the line for disconnecting said terminal therefrom, and for disconnecting said signaling device therewith, together with normally bridged bells and generators at the subscribers stations, a line relay, a local circuit for energizing said line relay, and bridging supervisory and ringing apparatus at the central station.

56. The combination with a telephoneline, of a connection-terminal and a signaling device, and means for automatically connecting said elements with, and disconnecting the same from, the line so that both of said elements are never in connection with the line at the same time, together with normally bridged bells and generators at the subscribers stations, a line relay, a local circuit for energizing said line relay, and bridging supervisory and ringing apparatus at the central station.

57. The combination with a telephoneline, of a connection-terminal normally disconnected therefrom, a signaling device normally connected therewith, a relay, and

means actuated by the act of making connection with the line for operating said relay to connect said terminal with the line and to disconnect said signaling device from the line, together with normally bridged bells and generators at the subscribers stations, a line relay, a local circuit for energizing said line relay, and bridging supervisory and ringing apparatus at the central station.

58. The combination with a telephoneline, of an individual connection-terminal for the line, a relay for connecting the same with and disconnecting the same from the a line, and a test-circuit controlled by said relay, together with normally bridged bells and generators at the subscribers stations, a line relay, a local circuit for energizing said line relay, and bridging supervisory and ringing apparatus at the central station.

59. The combination with a telephoneline, of an individual connection-terminal for the line normally disconnected therefrom, a relay, and means actuated by the act of making connection with the line for operating said relay to connect said terminal with the line, and a sleeve-circuit controlled by said relay, together with normally bridged bells and generators at the sub scribers stations, a line relay, a local circuit for energizing said line relay, and bridging supervisory and ringing apparatus at the central station.

60. The combination with a telephoneline, of a relay having a winding included in a localicircuit including contacts at a connection-terminal, a pair of springs or other movable parts actuated by said relay,

and connected respectively with the limbs of said telephone-line, back contacts against which said springs or parts normally rest, and a signaling device connected between said back contacts, front contacts with which said springs or parts engage when the relay is energized, and the line-contacts of a connection-terminal connected with said front contacts, together with normally bridged bells and generators at the subscribers stations, a line relay, a local circuit for energizing said line relay, and bridging supervisory andrringing apparatus at the central station.

61. In a telephone system, a line having two limbs extending to a central oflice, a

relay having a movable contact member for each limb of said line, a signal included in circuit between the back contacts'of said members, a spring-jack normally disconnected from said line and having its talking contacts included between the front contacts of said relay members, and a local circuit including the coil of said relay controlled at the spring-jack, whereby said signal is disconnected from said line and said jack is connected with said line when a connection is made at the jack, together with normally bridged bells and generators at the subscribers stations, a line relay, a local circuit for energizing said line relay, and bridging supervisory and ringing apparatus at the central station.

62. In a telephone system, a line having two limbs extending to a central office, a relay having a movable contact member for each limb of said line, a signal included in circuit between the back cont-acts of said members, a spring-jack normally disconnected from said line and having its talking contacts included between the front contacts of said relay members, and a local circuit controlled by additional contacts at the spring-jack, whereby said signal is disconnected from said line and said jack is connected with said line when a connection is made at the jack, together with normally bridged bells and generators at the subscribers stations, a line relay, a local circuit for energizing said line relay, and bridging supervisory and ringing apparatus at the central station.

63. In a telephone system, the combination of a line signal device, a battery for holding the line signal device in operation, and a generator adapted for supplying cur rent through the battery for the purpose of initially operating the line signal device and thereby causing the latter to include itself in a closed battery circuit, which battery circuit insures the display of the line signal until the operator answers the call.

64. In a telephone system, the combination of the line relay, the cut-0E relay, and the generator and hook-switch and battery and plugs and jacks for operating and controlling the same, and means operated by the line relay for short circuiting the line when the subscriber calls, substantially as described, and an electric magnet excluded from the talking circuit for giving a disconnect signal.

65. In a telephone system, a subscribers line, a line relay provided with means for short circuiting the line when the subscriber calls, by a normally open connection between the two sides of the line, a magneto by which the subscriber initially energizes said relay, and a battery for then keeping said relay energized over the short circuit.

66. In a telephone system, a subscribers line, a line relay provided with means for short circuiting the line when the subscriber calls, and a condenser in the line.

67. In a telephone system, a subscribers line normally closed at the substation thereof, a condenser in the line, in the path of the voice and ringing currents, so that the subscriber of said line talks through said condenser, and a line signal and a source of current normally bridged across the line.

68. In a telephone system, a subscribers line, a ack and a line signal therefor, a sub station source of current for calling, a central source for keeping the line signal displayed until the operator answers, and means for automatically retiring the line signal and connecting the jack with the line when the operator answers the call.

69. In a telephone system, a subscribers line, a jack normally disconnected therefrom, a line signal and a cut-off relay,means for energizing a cut off relay to retire the line signal and connect the jack with the line, a jack normally disconnected therefor keeping the line signal displayed until the operator answers.

70. In a telephone system, a subscribers line normally closed at the substation thereof, a battery normally bridged on the line, and a condenser in the line, in the path of the voice and ringing currents, so that the subscriber of said line talks through said condenser.

71. In a telephone system, a subscribers line, a jack normally disconnected there from, a cord circuit having only two strands, said strands constituting part of the talking circuit, a supervisory mechanism bridged across the cord circuit, means for signaling the subscriber by projecting ringing current over both sides of the said line, and a central battery for signaling bridged across the line.

72. In a telephone system, a subscribers line, a ringer normally bridged thereon, a jack normally disconnected therefrom, supervisory mechanism adapted to be included in bridge of the talking circuit, means for operating said ringer by projecting signaling current over both sides of the said line, and a central battery for signaling bridged across the line.

73. In a telephone system, a subscribers line, a jack normally disconnected therefrom, means for signaling the subscriber by projecting ringing current over the two sides of said line in series, a cord circuit having only two strands, relay mechanism bridged across the cord circuit between the said strands, means for operating said supervisory mechanism when the subscriber hangs up his telephone, and a central battery for signaling bridged across the line.

74. In a telephone system, a subscribers line, a ringer bridged across the same, a line signal and jack, means for operating said ringer over both sides ofthe line in series, means comprising a cut-off relay for automatically retiring the line signal and connecting the jack with the line when the operator answers, a cord circuit having only two strands, a supervisory mechanism bridged across the cord circuit between said strands, said supervisory mechanism responsive to the subscriber for giving a disconnect signal, and a central battery for signaling bridged across the line.

Signed by me at Chicago, Cook county, Illinois, this 22nd day of October 1901.

HENRY P. CLAUSEN. Witnesses:

CHAS. C. BULKLEY, HARRY P. BAUMGARTNER.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

